Return to signbitl_ieee754.c CVS log | Up to [cvs.NetBSD.org] / src / lib / libc / gen |
File: [cvs.NetBSD.org] / src / lib / libc / gen / signbitl_ieee754.c (download)
Revision 1.2, Fri Apr 26 09:03:47 2019 UTC (4 years, 11 months ago) by maya
Unify signbitl implementations. (Unclear why they were different, it was only the comments that differed) Add a comment describing why the generic version works for both 80-bit and 128-bit double. |
/* $NetBSD: signbitl_ieee754.c,v 1.2 2019/04/26 09:03:47 maya Exp $ */ /*- * Copyright (c) 2003 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Klaus Klein. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include <sys/cdefs.h> #if defined(LIBC_SCCS) && !defined(lint) __RCSID("$NetBSD"); #endif #include <machine/ieee.h> #include <math.h> #ifdef __HAVE_LONG_DOUBLE /* * 7.12.3.6 signbit - determine whether the sign of an argument is negative * IEEE 754 compatible 80-bit or 128-bit extended precision. * * Differences between 128-bit and 80-bit are handled by having a * different struct ieee_ext. */ int __signbitl(long double x) { union ieee_ext_u u; u.extu_ld = x; return (u.extu_ext.ext_sign == 1); } #endif /* __HAVE_LONG_DOUBLE */